/// <summary>Update a resource from a xml-source.</summary>
/// <param name="xamlSource"></param>
/// <returns></returns>
protected async Task <object> UpdateResourceAsync(XmlReader xamlSource)
{
var resourceKey = (object)null;
object resource;
try
{
// create the resource
using (var elementReader = await xamlSource.ReadElementAsSubTreeAsync(XmlNamespaceScope.ExcludeXml))
{
var startObjectCounter = 0;
resource = await PpsXamlParser.LoadAsync <object>(elementReader,
new PpsXamlReaderSettings()
{
FilterNode = (reader) =>
{
switch (reader.NodeType)
{
case XamlNodeType.GetObject:
case XamlNodeType.StartObject:
startObjectCounter++;
goto default;
case XamlNodeType.EndObject:
startObjectCounter--;
goto default;
case XamlNodeType.StartMember:
if (startObjectCounter == 1 && reader.Member == XamlLanguage.Key && resourceKey == null)
{
resourceKey = reader.ReadMemberValue();
return(reader.Read());
}
goto default;
default:
return(true);
}
},
CloseInput = false,
Code = this,
ServiceProvider = this
}
);
}
if (resource == null)
{
throw Procs.CreateXmlException(xamlSource, "Resource load failed.");
}
// check the key
if (resourceKey == null)
{
var style = resource as Style;
if (style == null)
{
throw Procs.CreateXmlException(xamlSource, "x:Key is missing on resource.");
}
resourceKey = style.TargetType;
}
}
catch (XmlException) // no recovery, xml is invalid
{
throw;
}
catch (Exception e) // xaml parser error
{
// check resource key
if (resourceKey == null || // no resource key to check, do not load
defaultResources[resourceKey] == null) // no resource, might be imported
{
throw;
}
else
{
var message = $"Could not load resource '{resourceKey}'.";
if (e is XamlParseException)
{
AppendException(e, message);
}
else
{
AppendException(Procs.CreateXmlException(xamlSource, message, e));
}
return(null);
}
}
// update resource
//Debug.Print("UpdateResouce: ({1}){0}", resourceKey, resourceKey.GetType().Name);
defaultResources[resourceKey] = resource;
return(resourceKey);
} // func UpdateResource